<template>
  <div class="app-container">
    <h2 style="text-align: center">发布新课程</h2>

    <el-steps
      :active="1"
      process-status="wait"
      align-center
      style="margin-bottom: 40px"
    >
      <el-step title="填写课程基本信息" />
      <el-step title="创建课程大纲" />
      <el-step title="最终发布" />
    </el-steps>

    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input
          v-model="courseInfo.title"
          placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"
        />
      </el-form-item>

      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类"
          @change="subjectLevelOneChanged"
        >
          <el-option
            v-for="subject in subjectOneList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
          <el-option
            v-for="subject in subjectTwoList"
            :key="subject.value"
            :label="subject.title"
            :value="subject.id"
          />
        </el-select>
      </el-form-item>

      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select v-model="courseInfo.teacherId" placeholder="请选择">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"
          />
        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number
          :min="0"
          v-model="courseInfo.lessonNum"
          controls-position="right"
          placeholder="请填写课程的总课时数"
        />
      </el-form-item>

      <!-- 课程简介 TODO -->
      <el-form-item label="课程简介">
        <el-input v-model="courseInfo.description" placeholder=" " />
      </el-form-item>

      <!--课程封面-->
      <el-form-item label="课程封面">
        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API + '/eduoss/fileoss'"
          class="avatar-uploader"
        >
          <img :src="courseInfo.cover" />
        </el-upload>
      </el-form-item>

      <el-form-item label="课程价格">
        <el-input-number
          :min="0"
          v-model="courseInfo.price"
          controls-position="right"
          placeholder="免费课程请设置为0元"
        />
        元
      </el-form-item>

      <el-form-item>
        <el-button
          :disabled="saveBtnDisabled"
          type="primary"
          @click="saveOrUpdate"
          >保存并下一步</el-button
        >
      </el-form-item>
    </el-form>
  </div>
</template>
<script>
import course from "@/api/edu/course";
import subject from "@/api/edu/subject";
export default {
  data() {
    return {
      saveBtnDisabled: false, // 保存按钮是否禁用
      courseInfo: {
        title: "",
        subjectId: "",
        teacherId: "",
        lessonNum: 0,
        description: "",
        cover: "https://guli-edu-202112.oss-cn-beijing.aliyuncs.com/01.jpg",
        price: 0,
        subjectParentId: "", //一级分类id
        subjectId: "", //二级分类id
      },
      courseId: "",
      teacherList: [],
      subjectOneList: [],
      subjectTwoList: [],
      BASE_API: process.env.VUE_APP_BASE_API,
    };
  },

  created() {
    if (this.$route.params && this.$route.params.id) {
      this.courseId = this.$route.params.id;
      this.getInfo();
      this.getListTeacher();
    } else {
      this.courseInfo = {
        title: "",
        subjectId: "",
        teacherId: "",
        lessonNum: 0,
        description: "",
        cover: "https://guli-edu-202112.oss-cn-beijing.aliyuncs.com/01.jpg",
        price: 0,
        subjectParentId: "", //一级分类id
        subjectId: "", //二级分类id
      };
      this.getListTeacher();
      this.getOneSubject();
    }
  },

  methods: {
    getInfo() {
      course.getCourseInfoId(this.courseId).then((response) => {
        this.courseInfo = response.data.courseInfoVo;
        //查询出所有分类
        subject.getSubjectList().then((response) => {
          this.subjectOneList = response.data.list;
          for (var i = 0; i < this.subjectOneList.length; i++) {
            //获取每个一级分类
            var oneSubject = this.subjectOneList[i];
            //比较当前courseInfo的id 与一级分类的if是否相等
            if (this.courseInfo.subjectParentId == oneSubject.id) {
              //获取所有一级分类里面的二级分类
              this.subjectTwoList = oneSubject.children;
            }
          }
        });
      });
    },

    //添加课程
    addCourse() {
      course.addCourseInfo(this.courseInfo).then((response) => {
        //提示
        this.$message({
          type: "success",
          message: "添加课程信息成功!",
        });
        //跳转到第二步
        this.$router.push({
          path: "/course/chapter/" + response.data.courseId,
        });
      });
    },

    //修改课程
    updateCourse() {
      course.updateCourseInfo(this.courseInfo).then((response) => {
        //提示
        this.$message({
          type: "success",
          message: "修改课程信息成功!",
        });
        //跳转到第二步
        this.$router.push({
          path: "/course/chapter/" + this.courseId,
        });
      });
    },

    saveOrUpdate() {
      //判断是添加还是修改
      if (!this.courseInfo.id) {
        this.addCourse();
      } else {
        this.updateCourse();
      }
    },

    getListTeacher() {
      course.getListTeacher().then((response) => {
        this.teacherList = response.data.items;
      });
    },

    getOneSubject() {
      subject.getSubjectList().then((response) => {
        this.subjectOneList = response.data.list;
      });
    },

    subjectLevelOneChanged(value) {
      for (let i = 0; i < this.subjectOneList.length; i++) {
        if (this.subjectOneList[i].id === value) {
          this.subjectTwoList = this.subjectOneList[i].children;
          this.courseInfo.subjectId = "";
        }
      }
    },

    handleAvatarSuccess(res, file) {
      this.courseInfo.cover = res.data.url;
    },

    beforeAvatarUpload(file) {
      const isJPG = file.type === "image/jpeg";
      const isLt2M = file.size / 1024 / 1024 < 2;

      if (!isJPG) {
        this.$message.error("上传头像图片只能是 JPG 格式!");
      }
      if (!isLt2M) {
        this.$message.error("上传头像图片大小不能超过 2MB!");
      }
      return isJPG && isLt2M;
    },
  },
};
</script>
<style scoped>
.tinymce-container {
  line-height: 29px;
}
</style>